Figure 1.

Experimental trial. Each trial consists of a sequence of six rhythmically presented stimuli. The initial stimulus is presented on either the left (L) (illustrated) or right (R), and subsequent stimuli are presented progressively closer to the center. The target stimulus is always presented at the center. Participants judge whether the auditory frequency of the target stimulus is higher or lower (illustrated) than for preceding stimuli. Stimuli consist of simple bars and tones presented together, with visual–auditory onset asynchrony values of 0, 30, 50, 65, 75, or 100 ms. Visual stimuli are represented as small white bars in the gray rectangles. Auditory stimuli from the left and right auditory channels are shown as sine waves below. The relative amplitude of the two channels is used to manipulate apparent spatial position of the auditory stimuli. The target stimulus shown here is lower in frequency than the preceding stimuli. Note the delay between onsets of each visual stimulus and the corresponding auditory stimulus, which remains constant for each trial.